conda虚拟环境下使用catkin_make编译报错`Could NOT find PY_em (missing: PY_EM) `

报错：

Using PYTHON_EXECUTABLE: /home/tjsiasun/miniconda3/envs/pointpillar2/bin/python3
-- Using Debian Python package layout
-- Could NOT find PY_em (missing: PY_EM) 
CMake Error at /opt/ros/noetic/share/catkin/cmake/empy.cmake:30 (message):
  Unable to find either executable 'empy' or Python module 'em'...  try
  installing the package 'python3-empy'
Call Stack (most recent call first):
  /opt/ros/noetic/share/catkin/cmake/all.cmake:164 (include)
  /opt/ros/noetic/share/catkin/cmake/catkinConfig.cmake:20 (include)
  CMakeLists.txt:58 (find_package)

解决：

编译时指定python环境

catkin_make -DPYTHON_EXECUTABLE=/usr/bin/python3